1. Field of the Invention
The present invention generally relates to a toner container detachably attached to the main body of an image forming apparatus to supply toner to be used in the image forming process, and the image forming apparatus including the same.
2. Description of the Related Art
In conventional image forming apparatuses using an electrophotographic system such as copying machines, printers, facsimiles, or multifunction products provided with these functions, a cylindrical toner container for supplying toner to a developing device is known (see, for example, Patent document 1).
In Patent document 1 and the like, a toner container (toner bottle) replaceably installed in a toner-container holder (bottle holder) of the main body of the image forming apparatus mainly includes a container body and a held portion (cap portion). A spiral-shaped projection is provided along the inner circumferential surface of the container body, and the toner contained in the container body is conveyed toward an opening through rotation of the container body. The held portion communicates with the opening of the container body, and it is non-rotatably held by the toner-container holder, i.e., it does not rotate with the container body. The toner output from the opening of the container body is discharged from a toner outlet provided in the held portion. Thereafter, the toner discharged from the toner outlet of the held portion is supplied to the developing device.
The toner container configured in the above manner can reduce toner stain upon replacement of the toner container as compared with toner containers (see, for example, Patent document 2) each of which has no held portion and directly supplies toner from the opening of the container body to the developing device. More specifically, because the toner outlet of the held portion is opened or closed in synchronization with part of attachment/detachment operation (rotating operation) of the toner container, such trouble that the user's hands become stained with toner by touching the toner outlet can be suppressed. Further, the toner outlet is formed downwardly in the lower part of the toner container in the vertical direction, and when the toner container is getting empty, the amount of toner near the toner outlet can be reduced due to the drop by its own weight. Therefore, the toner stain in the toner outlet upon replacement of the toner container is reduced.
More specifically, in Patent document 1 and the like, when the toner container is to be attached to the toner-container holder in the main body of the apparatus, at first, a main-body cover (stack portion) is opened upwardly and the toner-container holder is exposed. Then, the toner container is placed on the toner-container holder from the upper side thereof. Thereafter, a handle integrally provided to the held portion is held, so that the held portion is rotated (rotating operation). With this operation, an engaging portion formed in the end face of the held portion is engaged with a positioning member of an apparatus body, and the position of the toner container in the toner-container holder is fixed. Furthermore, the toner outlet provided in the held portion is moved to the lower part in response to the rotation of the held portion, and a shutter opens the toner outlet downwardly so as to resist the biasing force of a spring.
On the other hand, Patent document 3 or the like discloses a toner storage container (toner container) having a bag container and a cap member. A toner outlet of the cap member is opened/closed in synchronization with a partial operation (rotating operation of an open/close folder) of the attachment/detachment operation of the main body provided a screw pump, for the purpose of reducing toner stain (toner scatter) occurring upon the attachment/detachment operation.
More specifically, when the toner storage container is attached to the apparatus body, at first, an open/close holder (open/close folder) is rotated around a hinge and the upper side of the open/close holder is exposed. Then, the toner storage container is set in the open/close holder. Thereafter, the open/close holder with the toner storage container set therein is rotated (rotating operation) around the hinge. With this operation, an engaging portion provided on both side faces of a cap member so as to sandwich the toner outlet is engaged with a positioning member of the apparatus body, and the position of the toner-container holder in the apparatus body is fixed. Furthermore, a plug member (shutter member) is pushed by a nozzle (toner conveying pipe) in response to the rotation of the open/close holder so as to resist the biasing force of a spring, to open the toner outlet sealed by a packing (G seal).
In the toner storage container described in Patent document 3 or the like, the plug member is pushed by the nozzle (toner conveying pipe) in synchronization with the opening operation of the open/close holder to open the toner outlet sealed by the packing. It can thereby be expected to obtain the effect of reducing the occurrence of toner stain.
However, there is a disadvantage such that the toner amount of the toner storage container cannot be increased, which leads to an increase in the replacement frequency of the toner storage container. More specifically, the toner storage container has a bag container which contains toner and is provided along the vertical direction as its longitudinal direction. Therefore, if the toner amount is desired to be increased, the height of the toner storage container is inevitably increased. This causes the height of the open/close holder to be increased, to affect the layout in the height of the whole image forming apparatus. Therefore, the toner amount of the toner storage container cannot be increased so much, and the replacement frequency thereby increases more as compared with the toner containers (of which longitudinal direction is the horizontal direction) according to Patent document 1 and the like.
In conventional image forming apparatuses using an electrophotographic system such as copying machines, printers, facsimiles, or multifunction products provided with these functions, a cylindrical toner bottle for supplying toner to a developing device is known (see, for example, Patent document 4).
In Patent document 4 or the like, a toner bottle replaceably provided in the main body of the image forming apparatus mainly includes a bottle body (container body) and a case (container supply unit). A spiral-shaped projection is provided in the inner circumferential surface of the bottle body, and the toner contained in the bottle body is conveyed toward an opening through rotation of the bottle body. The case communicates with the opening of the bottle body, and is held by the main body of the image forming apparatus without following the rotation of the bottle body. The toner discharged from the opening of the bottle body is discharged from the toner outlet (toner supply port) provided in the case. Thereafter, the toner discharged from the toner outlet of the case is supplied to the developing device.
The toner bottle configured in the above manner allows improvement of the operability/workability for the user to replace toner bottles, as compared with the toner bottle (see, for example, Patent document 5) which has no case provided therein and directly supplies the toner from the opening of the bottle body to the developing device. More specifically, because the toner outlet of the case is opened/closed in synchronization with attachment/detachment operation of the toner bottle, such trouble that the user's hands become stained with toner by touching the toner outlet can be suppressed.
On the other hand, Patent document 4 discloses a technology for a toner bottle including a bottle body and a case, in which to prevent such a failure as toner leakage from a gap between the bottle body and the case, a seal member (seal) for sealing a gap between mutually opposite areas of the bottle body and the case is provided around the opening of the bottle body. Further, another technology of using a concave-shaped seal member is disclosed.
Patent document 1: Japanese Patent Application Laid-Open No. 2004-287404
Patent document 2: Japanese Patent Application Laid-Open No. 2000-338758
Patent document 2: Japanese Patent Application Laid-Open No. 2004-161371
Patent document 4: Japanese Patent Application Laid-Open No. 2000-214669
Patent document 5: Japanese Patent Application Laid-Open No. 2003-233248
Each of the toner containers (toner container including a container body and a held portion) disclosed in Patent document 1 or the like has features such that there is less toner stain upon replacement of the toner containers and the replacement frequency can be reduced because the toner amount in the toner container can be increased.
However, when the user, the seller, the distributor, and the manufacturer stock the toner containers (which are not yet used before being set in the image forming apparatus), and if the toner container is stood on a horizontal plane (an arbitrary plane for placing) with the held portion directed vertically downward, the toner on the side of the held portion may sometimes be aggregated.
In other words, when the held portion is directed downward, the toner is deposited on the side of the held portion by its own weight, which may lead to toner aggregation. If the toner container with the toner aggregated on the side of the held portion is set in the image forming apparatus, the toner is insufficiently discharged from the toner outlet, which also causes the toner not to be supplied sufficiently to the developing device. Furthermore, if a toner lump is produced caused by the toner aggregation, this may cause a failure in toner conveyance or an abnormal image.
These problems quite often occur especially when the toner container with the held portion directed vertically downward is left standing for a long time or under high-temperature and high-humidity environments.
The present invention has been achieved to solve at least the conventional problems, and it is an object to provide a toner container and an image forming apparatus in which toner is never aggregated on the side of its held portion when the toner container is stocked.
Each of the toner containers disclosed in Patent document 1 or so has less toner stain in the toner outlet as compared with that in Patent document 2 or so, and therefore, it can be expected to obtain the effect of preventing such trouble that the user's hands become stained with toner by touching the toner outlet. However, the toner containers in Patent document 1 or so are disadvantages in terms of operability/workability upon its attachment/detachment (replacement).
A first disadvantage is such that the attachment/detachment operation to/from the toner-container holder is implemented with a plurality of operations. More specifically, the attachment/detachment operation of the toner container includes the plurality of operations such as an operation of opening/closing the main-body cover, an operation of placing/removing the toner container on/from the toner-container holder, and an operation of rotating the held portion.
A second disadvantage is such that it is difficult for the user to check that the operation is performed properly nearly until the completion of the attachment operation. More specifically, the user cannot feel certain that the operation is correct at the point in time when the operation of opening the main-body cover and the operation of placing the toner container on the toner-container holder are complete. Thereafter, by rotating the held portion to fix the position of the held portion, the user gains a click feeling of the held portion, and feels certain that no erroneous operation is done.
A third disadvantage is such that the upper side of the toner-container holder is restricted in terms of layout. More specifically, to place the toner container on the toner-container holder from the upper side, the operation of opening/closing the main-body cover in the vertical direction is needed. Therefore, it is necessary to ensure space required for layout to open/close the main-body cover and place/remove the toner container. This causes reduction in operability/workability in attachment and detachment of the toner container when a scanner (document reader) or the like is provided above the toner-container holder.
On the other hand, in the toner storage container described in Patent document 3 or the like, the plug member is pushed by the nozzle in response to the opening operation of the open/close holder, to open the toner outlet sealed by the packing. Therefore, the effect of reducing occurrence of toner stain can be expected. However, the toner storage container according to Patent document 3 or the like also has some disadvantages in terms of operability/workability upon its attachment/detachment.
A first disadvantage is such that the toner amount of the toner storage container cannot be increased and the frequency of replacement of the toner storage container therefore increases. The toner storage container has a longitudinal bag container for containing toner. The bag container is arranged so that it stands vertically. Therefore, if the capacity of the bag container is to be increased, the height of the toner storage container needs to be increased. This causes the height of the open/close holder to be increased, to affect the layout in the height of the whole image forming apparatus. Therefore, the toner amount of the toner storage container cannot be increased so much, and the replacement frequency increases thereby as compared with the toner containers (in which the horizontal direction is set as the longitudinal direction) according to Patent document 1 and the like.
A second disadvantage is such that it is difficult for the user to feel certain that no erroneous operation is done. More specifically, because the plug member opens/closes the toner outlet in synchronization with the open/close operation of the open/close holder, it is difficult for the user to feel if the toner outlet is actually opened or closed because the user does not touch the toner storage container during the operation.
The present invention has been achieved to solve at least the conventional problems, and it is an object of the present invention to provide a toner container with high operability/workability during its replacement and capable of reliably reducing occurrence of toner stain, and an image forming apparatus including the same.
Because there has been the increasing awareness for protection of environmental resources, high recycling rates (easiness of recycling) are required for toner containers. More specifically, it is demanded that the toner container is configured to be easily filled with toner when it is newly produced, and that in addition to this feature, the toner container is configured to be easily filled with toner when it is recycled without main members of the container being disassembled.
The toner bottle described in Patent document 4 may sometimes has some advantages such that the operability/workability upon the replacement is improved as compared with that of Patent document 5, but also has some disadvantages such that toner may be leaked from a gap between the bottle body and the case after the time elapsed.
More specifically, the seal member, such as polyurethane foam bonded to an area of the case side which faces the opening, slidably contacts the opening of the rotating bottle body, to prevent leakage of the toner from the gap between the case and the bottle body. On the other hand, by rotating the bottle body which is held improperly as compared with the case which is firmly held by a holding portion of the main body of the image forming apparatus, the bottle body rotates while slightly vibrating in its radial direction (the direction orthogonal to the rotating-axis direction). Such vibrations in the radial direction of the bottle body are repeated over time, the sealing capability of the seal member gradually deteriorates. In other words, the opening is radially vibrated again and again, a deformed shape of the seal member having elasticity (shape to seal the gap) is not fixed, and the restoring force thereof deteriorates, which results in occurrence of a gap in the space which should be sealed. And the toner is leaked from the gap to the outside of the toner bottle. If the toner is leaked to the outside of the toner bottle in this manner, the toner is wasted, and the inside of the image forming apparatus is contaminated with the toner.
These problems are not negligible particularly for large-capacity toner bottles produced to reduce the running cost. In other words, to rotate such a toner bottle that the filling amount of toner is increased and the weight of the toner bottle is thereby increased, a large driving force is required. Therefore, the amount of vibration in the radial direction of the opening increases associated with an increase in the torque, uneven rotation, vibration of the bottle body. Furthermore, the operation time (life) of the toner bottle having the large capacity is increased according to the toner amount increased, which causes the time for which the vibration of the opening is affected on the seal member to be increased.
On the other hand, Patent document 4 or the like discloses a technology for forming a concave-shaped seal member with which the gap between the bottle body and the case is sealed. However, even if the seal member with elasticity is formed into the concave shape, this shape does not help control the radial vibration of the opening. The effect of directly resolving the problems cannot thereby be expected.
The present invention has been achieved to solve at least the conventional problems, and it is an object of the present invention to provide a toner bottle with high operability/workability during its replacement and without toner leakage over time even if it is increased in capacity, and an image forming apparatus using the same.